SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2479e86a6550a4b3c230da38af821f4fb521b3a9be8b53aa803dcc7fb53d0fb5' 
  AND token = 'JoH7F/DLB8HHeuL1C5opVwfnIG6IVREokH77dz9rJv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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