SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a5f1a8d00d225fdc8ff21cc791670c54b105b3ca6128743c7014b7583310cb5' 
  AND token = 'dWY7M+a05I1Bqxz/kqwtGgmXwyuzmU7I8jV/9aegiBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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