SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0686aa22b76b0d2561fc2cd3e9c841556d360d773eb87c65792230e26dcc4b4' 
  AND token = 'LMGH8GKoaEnzzo6NTE8qmgEEfAcmOTXnvgNTz5pC10o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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