SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f3c1d85432524cc0e7a4e8b37eb6d7e8196290ed46fcc80c1d99fbe7693341' 
  AND token = 'XOsZeoxjNP1+F49JbwxQWSPJNx4xKkPVh8eRF2JN3G0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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