SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '41e6de10a6044c04732990fb77247e91e7c15257b11c1752d05e4012f2b4077d' 
  AND token = '8lqZgQoNRuPlYwTkbltUd129e+WQo03MFipb1Y6K+60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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