SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '793632c4dda21610003dd584d95e7fa83bd823a032413b8ef2f2aa56028295a8' 
  AND token = 'nl+ofZRXYbNhm/rxIcGWXbmMA/gqnVGYXarzvMFX1xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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