SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8b33c339eb89c1cddcecb2c0fe762d9775fb1d24939197214ffc1c1a85a80c55' 
  AND token = 'BvqbU6Yvu+RLTfBezJ3foROD6WxdGgZrgnrcjpLsT8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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