SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cc916d29f4747ea0eb461eeb9d737369a854e0ae47b1ea56765194af504335c' 
  AND token = 'QXovie+HPMxsaHJBsVG7KyDx0NI1vfP3aLVF8JzaQRs=' 
  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"
    }
  }
}