SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdf141e5506132971e93216be7945f45536d695561f7a2faa9ac934bb5e2fb2d' 
  AND token = 'B41Yxw0mpjJNRA95Vckq31uoOyKYHW00ZxnNr4SUwV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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