SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92fbe5f9a57adfe44e0db7d6cab8598f0bd62b158618a72941d791ba4a6cb8b3' 
  AND token = 'aIm4gsTe8SPpCYhS/TGjnhpdzTqGMKlFMZ5pPMWmWQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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