SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2144a84150eaa500c04a2f2832a45aca32c17b2c4416ae01b0ac386140fc870' 
  AND token = 'hhofCtHxLr/nrxJuyyCg1DjeAK3s6xYcxYQz+cWUH0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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