SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5b212b7cccf1c6a34ee0c2f77401cf4bc94107387d430f34f8e1ed30cc357736' 
  AND token = 'YXpRYHwzmhpa5LRxj8EKinLBsmrPw88V/g8EUREs20Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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