SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f4ab53d0e9247df31086f2b976d2ee82eeca268fd76e588242fd4caaaf3c7bd' 
  AND token = 'Wbg4HiXMeLhqdF6n97V0Oh/xDsLTi7+0RRzbBUTWVB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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