SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25e121a596c57452f559adfdf85c85b16c22df8eaef7d2262effd848c2c71c1b' 
  AND token = 'MOUDR0vKNknUeDmKUsh3nKDiHpdTyd69Qzxy0/xSObY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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