SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '185bbcbb2d4cb892e005412025f8ba39e99328a477b6f9b809c91016a96f3157' 
  AND token = 'ec5RQj1BDcQblqGIGppRFkVIdXCM87dggJiUouAy0gA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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