Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6f474c7f15f90ee911239e4e55f6de50dfef64dfa031a3e6c22b419d50aab40' 
  AND token = 'MeGMe0f/Kqwswy3d7aV8UUJnFmrjbcMq97mNH8cnEM4=' 
  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"
    }
  }
}