SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd87be4a89f5bdcababb6af507daaa58db0b266d0b15a5bc2f286b45be6902af2' 
  AND token = 'znEOEqlT+vk+gtpIpSjcG4QE5+I6ufPaPhBiXvLboOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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