SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe64a3bd65ad322dc3738c3196999f720e2b53e4b9f85d292cc1c1c2f6365926' 
  AND token = 'S6pG8YX2X7RFl4EeZzt/dZxgRJ2akUznHUUs5gSmm8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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