SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbcecea4da736a4bd8b24674715de557aef4105e7f0264e881056394fd8aab58' 
  AND token = 'm7rL16nQ6kaYb+KS9stteNruR2G75Di4JQxbMBO7+F4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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