SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7b10a068f0c5e135f716c26900b4b76134ab13530f5ec81c286bce9b9f16db4e' 
  AND token = 'ZNW6gAfav2iplgTXAxGy52wspxWsGI3m/nW4HOBVJDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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