SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '48dd8a3aeb1785fa00a98f890c94472ee8aa9798e5b0ecd94fd48f5c4841eb75' 
  AND token = 'pjPwVuAQjizJ9iiDbNwVKd5ieuhMHhF90PKh43JD+4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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