SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3cc036def987d3e28a15cde77678b1f49b480594c0fcad30fc306c4d09acf5cf' 
  AND token = 'QoHB//C/KuNxH14fgVZ2cH9rV+X4TQyRmUzlsghApvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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