SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f8713e8acbc6a7287817b80f09f8ac885e4a450769a0f5228f105e7bd740e79' 
  AND token = 'qeBupc51IsH2O5DNC6VE3ecIbPohaEEBdloBWbMLeZI=' 
  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"
    }
  }
}