Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'fcff6da263df2c6a66b2cf92fc623f67e29726a12157f9cea8072d8021a8a1d9' 
  AND token = '4hbqUvcF2uw3xTSEwhRL7RuHWg9r1U2xomi1JX3Jy9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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