SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a610aa493fab9ab09ab3a120cc8be6cffb306dc65e63d22aee68f6997fca28e6' 
  AND token = 'b1q+Kz0gvhCkTLfgNrEubPqYhTJsUGwv0MJZoslpzQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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