SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec31b41e04fb353cf46fb637f029731c8c45b7bc81a9d7c871f07581d542e18d' 
  AND token = 'A6HfIQGgx7aKPMdKR4iicRC/7DbwiQOhhRtopRZeExY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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