SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74ea0b8dbea79925d70e1347dbb9f02c0e2eceada02907de88f27146a9528d03' 
  AND token = 'CKMkB6QfXshymhUAlIayzh2jqrWiUmWr+mJz4hi9dBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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