SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f80cd59e8cc090fd7ef669812fcb18546f0fa930c6400eaa23fee9f8f7b1637c' 
  AND token = '7PuPZKCFvMewB5YeunnNnYEryhNKUrqffVRByZSFdoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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