SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9cb3192cdbb9726bc0a4d340d5246bab0a6cc120d50af813faa720d8b578b49' 
  AND token = 'PqIhkaWqNIRwqEY7k2vyaqT3xg5x8jm3aAv6cjA20l4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}