SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b4ac9ae30e819d52539c2fe7d04ffa828e802b877d9f09d8c1af542209539f2' 
  AND token = '5P9ClQsZYEKsLUMujkMv/EGocfBNzt4zznpmnI9JpR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00136

JSON explain

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