SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fb709dac27b6d20f97c36bdad0c6b42e3026eb2e9855553e147c30fa06dc6d3' 
  AND token = 'dY5oDgbPA7lrjBcfnrsobQ4VnQasLq3mletOJE91fS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}