SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cc2db523b366eff68af8938e9f0eeaa9517378392ce386c2e4695bc9bed08fa' 
  AND token = '6l2GSitnoLwWL+vIgw2PYq/JBCyZrgv5L3jizKcXBtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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