SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2e73d8cf37dc664e58025e82ae294021a071570d70cf31685a78c0776542b47a' 
  AND token = 'FyP2u+Z7MFFHzZQwlPl/oiQS9Sl63tu7ynE5ZY0lyuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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