SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1ed5a4798df18c2c084a699f7e36c6916e111ade248ed1c6a4e9929f9d8d0540' 
  AND token = 'X+ZavDPkO4pR/4gGuJkznJyQRdwyN6acOOFqxpk93Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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