Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '303b2bbe6b1c501cb989b20d09cf42315a2ee445fc89fc74bc3785d7bc3e04dc' 
  AND token = '+Ns1uojbQvi1bvjZVVOIxFXO79CYsPCC7l/rre0Wtnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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