SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30e55d28baa53654fe2c4d7d527a5d8ce33d5b81372f1f2137bd084281344698' 
  AND token = 'kTZyzAKaU0zL+hb/CIrKdEpKtrvYlX2MKVpU6GQvC9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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