SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bbb97af6485f7f785fd9647bcad5449c88b091007bd35ade75dea4344b92df6' 
  AND token = 'B7sBh7B+zvINE8FjKJARNXTSAVeJlp6safrdXsUX/YM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}