SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e28a0c7cbf311376359b1d87ba7a75ff83cd0c2ef8fb68830341e19a883a9c7a' 
  AND token = 'iOz88SA+CPQZRUCk2rz52m/PjjWgNaP7VLIEiinYikY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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