SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec23d2c2ecb4c8c97b77b66789af52ddd5e2ce724e03a480bca81ff76aba49bd' 
  AND token = 'vvpDd5s1m3gbMwlQMnHa6VCcb7V16qEqXwNYBGS7ogU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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