SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '791254512b8f4fb544e9a957c45a91f613923fd58b70ed6055496bb8f2612299' 
  AND token = 'HMrpAiSvFE66m/dvdOcfRDaIeFQJ68Sv5WKI8X2CUK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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