SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2994cf7eba00f0567fa45bdad8e37fcc996e3b20897541432164911f7866ec12' 
  AND token = 'jyip25kCu38FzaP3/MmhYU8lrQSLbIHSBJH+XkWJ2ZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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