SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2c3cae3872f455b0b1932ed48e8f8a52546ddbee1657e3047a61272d9fb94c26' 
  AND token = 'JMBmm7S+2rwbUm5pW0/NvYxzKy0tWvKMRrdjKCucgQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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