SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd92eac91323b36d05c9b7bd1db91bcf8667cda088902ee4647f98da1fc0e5a5c' 
  AND token = 'drwWvLHp+s4x0jFzOigpqQVMWNX0DQBd7N3AWuDY3QU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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