SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52ba4b026c5db43d02cd43dc6e0fc2a7c9564c64b9a40b4bfbcf88e04ff95457' 
  AND token = 'qF9T6QJQKmVRt1r631IbW+rsIbAlP/8QAopnUAj7+kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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