SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '14b4e40cdc69cc2539006ad0068aaf81872fc49a2f2e16f61cc1b479eed34f81' 
  AND token = 'DqIP7u184ibkuTJMDFsKn4yzp+mKyCslI79DBOmOSsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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