SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ce162c20850fc85d8aebb1931c7abc36c9f4d05137c357f0856b851aff99fbb' 
  AND token = 'k0LNIRPRZ2DGdHbyel20jOKHi/IoF9efNJWbPk9JA6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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