SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4917d83c496df9e65c6d7b7c44ca27b9c9759e9e91719addb7fc160d4563944' 
  AND token = 'VfcBfU4est7ZYDKFYJWCrNKz1x/+eIClvxCuJSNwjJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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