SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19ad5258b084ca43a67e2790622437b717bccfa9489f83891df91fb9779f79c4' 
  AND token = 'FPXRqtahpCNEAktcVwRtOF1rn9OaQ3jY6zB0fsOQMBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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