SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7ebae286a31a0fd7745857fb521333106836b9b618cf8a1f1f9355f632719bf' 
  AND token = 'k5edXoUAQGgfbNzb4SvDwt4M+0bDK5tYhoZQojUzTHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}