SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '8dce321e8690b5f303623c3ba684e7cf3b922a7a0f720a0eddd020334d5895fa' 
  AND token = 'YvCndasNbDKVtqSjOGgg/N2PCav+77PLQ7U8r55YdtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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