SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '346a1aa73d3e4d8136d1069b7e4025f560fcc8f0928ef07f6477a255916dc123' 
  AND token = 'MBwxi7um8D+W1KTNEh1mV19n9b6U+qK2vCC5iQPFycg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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