SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '782bb311dbd17edf179b4a7cd0814bc310c710d3d896dfbc91ab8040fb5f0d05' 
  AND token = 'DHGZ2D4uJ1F4Edl4D4e0xT5W91EO5GaGsZAvLgwtDW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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