Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd57ea8175df0f1fe14b65a907a0c0e8c369426c2bd725deb5e6b3b9a24b41f13' 
  AND token = 'v7wJCwkztuKauBiZdLU7Ip5Pz0AbfWtZceYk8VcLN5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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