SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e9ae4b5c8579e1b39dfe739cae5be162558addc132ef46212dac6675466fa8b' 
  AND token = 'COW0SNAp1qDr8e+wqrdn44ijox/wOR52kkZyYo53zM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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