SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd330d3aa326387b4ffa6bfeef7f7711fa034f96a946f7daf2db050b36bd34509' 
  AND token = 'iulGsgPqAWrYEQU03HIxOOqLfkZlB+b2ixC+r91qbBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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