SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f1ea18631814d8fc6577d7bca6d3137306dcdd45072cd0bea20404b20c240e' 
  AND token = 'jADs6X2E1sQ4Ehp2/7zk3H3z8eq2nsvSY7RegJUv62g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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