SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31518161e0bcd298e291ce21090ed2ef755515c87628854dad24d651a72adf68' 
  AND token = '0hNaoDR3TmZ41NdZU8U69IwrFHXQkllR1lSKfggU+J0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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