SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '58e98fc3b97932a716193e4a542e21bf369fd2c122a7c3e4cc01a4dc9001740f' 
  AND token = 'lvS3dc7gc9RUsujqWHcCP6VM+uPyH8K5JdI1UAvXkQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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