SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37554ac9f7f5227dba2ad2de702fe16fd906e9c3e337721731fc948f4accbadc' 
  AND token = 'SCRhKoafgc74AJ4hE9hBEdOhULa1Vjj9YtZZYGPxQbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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