SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '59e88ba2ce1b1243a16a10931d17b9c27f1d79b6f06fc6ff354625d0a9ee2647' 
  AND token = 'Cmwk25tCcWLHfqrgsUFF9CQ1JzrNZ390ARkLpcaH0/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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