SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69a8bf54d702040328e25df69206074656742562d285c6041638b973bdd73324' 
  AND token = '/Vikihqx+uBkvuLM2lsyN8wqSMAMGmDo8AZHcR7g6nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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