SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8d4f14cd4cca6429319f9ac9238fbde17bfe860922d131d8d552461df6d8df9' 
  AND token = 'lP2M9d6Z/9BK/mu6iYPCYvm1Zfm6SNTerjraGB3cZ4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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