SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c923c836b106f621a6f4ee663a4e09898e782c6b078f848727d6a3a9f3f642ad' 
  AND token = 'Ezt3+8eiFUrb3k6hr8HpFZxaUdJsnPwHqNiysckIjsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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