SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56c587c216f3d1fc105523f2442ef91228225951aafa1e94ebcee1ac316e8323' 
  AND token = 'mCWFx8PuUHyi411/dUeOCLQ5vXpN7gXHiHhoSIdtERM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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