SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7708ab46d4c22a7be6d01e52451f61205983dc9b74eb8e11330b22653442f3c6' 
  AND token = 'YYTONQmzV9ELn0QZ6+vMQYQ+NDpGb5IL+tatpQczQCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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