SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5467bf5ebd52156b1f8f42d374084b7397ecf67f6047e768b4c6adf2118da012' 
  AND token = 'M39bgmzIZqFa3zFuPfeugTan1FiPwssZHFuU8AbUmVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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