SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29a7e18a364090f5b2346a6cae815702924b5e2d2d42297e0110b7325dcc2079' 
  AND token = 'Q82mIQWuemuywbY7qEXapQZr5MzB8XmiwM2c42yYW9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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