SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c88c44655a79115f3da297f92dd7e259aba4ce6481dfe9d71a47db6ff1dd434b' 
  AND token = '8fQ8tB0XtIX9RgZam5BwFN7l6ktwmyALYXVglsK5f2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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