SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae9089a298a3c468394dfecae41b2e36615de3f66c567176755a509ac731fc02' 
  AND token = 'EnMqGOLDsyaubAP/KufwCrusJrQ67lXJ/CFNMOU8/K8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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