SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7305c9e9fffabe229ff386b4a9561efbee790c4c5b1a71a501b8a553efb83862' 
  AND token = '9zWjnnDT1rD2Qqjx87cp7Pql5bSF79G/0/dtrUbztIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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