SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da2847700c08468ba27b3c593d9763eb063273054cb2e3df0c84a4665e0832f8' 
  AND token = 'TD9oys2T6VfZNAAYNrdBdOYiQYGEKI3yKoMSEqI6q3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}