SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1cd935179614c87697fff33687ca03495b63744d604b138af56b0b042e41b622' 
  AND token = 'nVQLuQ5/lCaUiBcvHBEr3NLvIpShgklCmjWF0nEKB0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}