SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fff0b16ccef2047ab58f741bd3c66b30ebd90484024582d4c6502c2f4f434a4' 
  AND token = 'SByGSUcRBULqqjEbw0Cxom7efFRwWjE1HKpoO2/N6wI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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