SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06a75e713b90a5bad9c2278dac75ac49ddce569d9e6a1c8b5a028d08210fd5be' 
  AND token = 'jxdSaqDARGioXwRqkJD3vFkxMRzUtLbh9I9qpyXJGqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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