SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da40d1980205289b63ecea49675c5daf6fd33a12005a5a1ecf3a3c2298d35a2f' 
  AND token = 'u0JeEPhyKFqwVjOBcnAi7O6L5jNOWpBbiZZD0/gP/nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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