SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7b9a1a46388bd7bced034663c9dfc3f48142c38329252f1b2cfe7f4848758a2' 
  AND token = 'Njdv0JW4eUWnZ/Gu4OnweGBMlhYETo31rH1WnCSVHgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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