SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3696b9191b7e245933c0286026a1448966024e70ae20cb375f280bb6d8056aba' 
  AND token = 'iALA6B9klbh8JRS2lfSUTQDfw3toW53K5blMcnxbPbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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