SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '053c52f7f7389ea27e126629296e18a409fc3f68aa5e4a0da6e7b15849cefd0d' 
  AND token = 'bKYBFitcoTCULlYQfQ4SlVsmUezfYuOuZv3HJNDA+6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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