SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa555b032e1020acccfd4824150d9eeaad7abc3e56a6196188e59fe3bb5be584' 
  AND token = 'j6xzAoQdkvmbZZMLD2iJv7Jg/Zvn3EpkspuUUGZEtr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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