SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fba5b5960fa403edb3238fd35d15983cf908e5fe9aa1f1940325e3878bb7a1b' 
  AND token = 'TrxRwfsfzCVzwZtyZiTi6dVcUnndTJrKaZEuJwXkDyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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