SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d1ea056a46b38ce2b6c4514002bc08449bb2838f930eb5b10f9e151fa770ee0' 
  AND token = '+0aNAlxEhSMWtwt3rLs740I1dojWxAXxvLP78rRVAtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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