SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '393047151958cb61501c78bc047aab2dea383a9376ca24a499e7889d1e4eef57' 
  AND token = 'EyGmCEszTRILZ2xpCwWBFFLrpv8vPbw/6qJeNBFJXGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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