SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56ae1c6e2f693308c365b7c67bedd402639ad52e9ca6a049ae7340820e8f57fb' 
  AND token = 'IIjIsWMMIRuDDtojEfS4Lmw7vswm+cEeQ72vfyhilGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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