SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '127f9d7f4957296bc48366bcad63af5543ee36ea28c1b56cd72ecfdba97f9698' 
  AND token = 'j9k5twEzInmm79UV5/gAQWkMqMrwLX4LjqNJeKOWimg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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