SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b5ac2352838368df90ade8e8b6540f3fa7b49a2c1208c0368b1fa7a9b1cc284' 
  AND token = 'qfNFgbAuZgOIY4R7E2WKk6Xd1qsvP/Yq4jUdx6vLLsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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